Sunday, April 29, 2007

Applied Phage Biology

I study bacteriophages, i.e. viruses that infect and destroy bacteria. Although no one has said it to my face, I figure some folks out there probably think that phages are somewhat of an odd choice of study organism. Weird even. But hey, I think they are cool. When I first saw a picture of them, I thought, this can't possibly be real. Check out the photo above (false color, FYI). Does it not look like a spasm from the over-active imagination of a science fiction author?

Anyway, lest it be believed that phages are solely biological curiosities of little interest for humans, I'd like to highlight the work of a biotechnology company in Maryland, Intralytix ,which recently gained FDA approval to market a novel defense against the food-borne bacteria, Listeria monocytogenes. Listeria causes listeriosis, which is responsible for ~500 deaths and 2,500 illnesses in Americans each year. Adhering to the dictum, "the enemy of my enemy is my friend", Intralytix's anti-Listeria treatment is a cocktail of six bacteriophages that can be sprayed on ready to eat foods such as hot dogs and deli meats. The phages are completely harmless to humans, but are deadly to the bacteria. In addition, the phages are highly specific to Listeria and should have no effect on our natural biofauna. These advantages are not shared by current antibiotic treatments, which are susceptible to being subverted by antibiotic resistance evolution, and moreover, are highly nonspecific and can kill many good bacteria as well.

Intralytix has treatments for E. coli and Salmonella in the pipeline as well. The E. coli O157:H7 treatment can be sprayed on raw hamburger and fresh vegetables, such as spinach, which was the source of a major outbreak causing 205 confirmed illnesses and three deaths last year. The Intralytix website also details applications in veterinary medicine, environmental sanitation, and human therapeutics.


  1. I also find that image to be impressive. How can something like a bacteriophage look like a little machine. Well, I guess it could be considered a machine... in it's own way.

    Great news about this company and the spray. Is there some sort of post-infection administration of the phage mixture available? Or does it only work before consumption?

    PS: The jump from your black background to the white and blue over at Intralytix left me blind for a couple seconds ;)

  2. Very cool. Upon first seeing such a photo of a bacteriophage, I too thought "this absolutely cannot possibly be real". Quite disturbing! And very cool.

  3. But hey, I think they are cool. When I first saw a picture of them, I thought, this can't possibly be real.

    My feelings exactly. I am often labeled a 'weirdo' for my curious fascination with bacteriophages.


  4. Arrowsmith, the hero of Sinclair Lewis's 1925 novel, used phage to treat human disease. I was really impressed by the author's insight into scientific thinking. Turns out he had a scientific collaborator, Paul de Kruif, who shared royalties although not sales.

    Ford Denison
    This Week in Evolution